net/can/can_core.c

   1 /*
   2  * CAN common CAN bus emulation support
   3  *
   4  * Copyright (c) 2013-2014 Jin Yang
   5  * Copyright (c) 2014-2018 Pavel Pisa
   6  *
   7  * Initial development supported by Google GSoC 2013 from RTEMS project slot
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a copy
  10  * of this software and associated documentation files (the "Software"), to deal
  11  * in the Software without restriction, including without limitation the rights
  12  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  13  * copies of the Software, and to permit persons to whom the Software is
  14  * furnished to do so, subject to the following conditions:
  15  *
  16  * The above copyright notice and this permission notice shall be included in
  17  * all copies or substantial portions of the Software.
  18  *
  19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  24  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  25  * THE SOFTWARE.
  26  */
  27
  28 #include "qemu/osdep.h"
  29 #include "chardev/char.h"
  30 #include "qemu/module.h"
  31 #include "qemu/sockets.h"
  32 #include "qapi/error.h"
  33 #include "net/can_emu.h"
  34 #include "qom/object_interfaces.h"
  35
  36 struct CanBusState {
  37     Object object;
  38
  39     QTAILQ_HEAD(, CanBusClientState) clients;
  40 };
  41
  42 static void can_bus_instance_init(Object *object)
  43 {
  44     CanBusState *bus = (CanBusState *)object;
  45
  46     QTAILQ_INIT(&bus->clients);
  47 }
  48
  49 int can_bus_insert_client(CanBusState *bus, CanBusClientState *client)
  50 {
  51     client->bus = bus;
  52     QTAILQ_INSERT_TAIL(&bus->clients, client, next);
  53     return 0;
  54 }
  55
  56 int can_bus_remove_client(CanBusClientState *client)
  57 {
  58     CanBusState *bus = client->bus;
  59     if (bus == NULL) {
  60         return 0;
  61     }
  62
  63     QTAILQ_REMOVE(&bus->clients, client, next);
  64     client->bus = NULL;
  65     return 1;
  66 }
  67
  68 ssize_t can_bus_client_send(CanBusClientState *client,
  69              const struct qemu_can_frame *frames, size_t frames_cnt)
  70 {
  71     int ret = 0;
  72     CanBusState *bus = client->bus;
  73     CanBusClientState *peer;
  74     if (bus == NULL) {
  75         return -1;
  76     }
  77
  78     QTAILQ_FOREACH(peer, &bus->clients, next) {
  79         if (peer->info->can_receive(peer)) {
  80             if (peer == client) {
  81                 /* No loopback support for now */
  82                 continue;
  83             }
  84             if (peer->info->receive(peer, frames, frames_cnt) > 0) {
  85                 ret = 1;
  86             }
  87         }
  88     }
  89
  90     return ret;
  91 }
  92
  93 int can_bus_filter_match(struct qemu_can_filter *filter, qemu_canid_t can_id)
  94 {
  95     int m;
  96     if (((can_id | filter->can_mask) & QEMU_CAN_ERR_FLAG)) {
  97         return (filter->can_mask & QEMU_CAN_ERR_FLAG) != 0;
  98     }
  99     m = (can_id & filter->can_mask) == (filter->can_id & filter->can_mask);
 100     return filter->can_id & QEMU_CAN_INV_FILTER ? !m : m;
 101 }
 102
 103 int can_bus_client_set_filters(CanBusClientState *client,
 104              const struct qemu_can_filter *filters, size_t filters_cnt)
 105 {
 106     return 0;
 107 }
 108
 109
 110 static bool can_bus_can_be_deleted(UserCreatable *uc)
 111 {
 112     return false;
 113 }
 114
 115 static void can_bus_class_init(ObjectClass *klass,
 116                                 void *class_data G_GNUC_UNUSED)
 117 {
 118     UserCreatableClass *uc_klass = USER_CREATABLE_CLASS(klass);
 119
 120     uc_klass->can_be_deleted = can_bus_can_be_deleted;
 121 }
 122
 123 static const TypeInfo can_bus_info = {
 124     .parent = TYPE_OBJECT,
 125     .name = TYPE_CAN_BUS,
 126     .instance_size = sizeof(CanBusState),
 127     .instance_init = can_bus_instance_init,
 128     .class_init = can_bus_class_init,
 129     .interfaces = (InterfaceInfo[]) {
 130         { TYPE_USER_CREATABLE },
 131         { }
 132     }
 133 };
 134
 135 static void can_bus_register_types(void)
 136 {
 137     type_register_static(&can_bus_info);
 138 }
 139
 140 type_init(can_bus_register_types);